/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.fn.stream;



import com.bff.gaia.unified.vendor.grpc.v1p13p1.io.grpc.stub.ClientCallStreamObserver;

import com.bff.gaia.unified.vendor.grpc.v1p13p1.io.grpc.stub.ClientResponseObserver;

import com.bff.gaia.unified.vendor.grpc.v1p13p1.io.grpc.stub.StreamObserver;



/**

 * A {@link ClientResponseObserver} which delegates all {@link StreamObserver} calls.

 *

 * <p>Used to wrap existing {@link StreamObserver}s to be able to install an {@link

 * ClientCallStreamObserver#setOnReadyHandler(Runnable) onReadyHandler}.

 *

 * <p>This is as thread-safe as the underlying stream observer that is being wrapped.

 */

public final class ForwardingClientResponseObserver<ReqT, RespT>

    implements ClientResponseObserver<RespT, ReqT> {

  public static <ReqT, RespT> ForwardingClientResponseObserver<ReqT, RespT> create(

	  StreamObserver<ReqT> inbound, Runnable onReadyHandler) {

    return new ForwardingClientResponseObserver<>(inbound, onReadyHandler);

  }



  private final Runnable onReadyHandler;

  private final StreamObserver<ReqT> inboundObserver;



  ForwardingClientResponseObserver(StreamObserver<ReqT> inboundObserver, Runnable onReadyHandler) {

    this.inboundObserver = inboundObserver;

    this.onReadyHandler = onReadyHandler;

  }



  @Override

  public void onNext(ReqT value) {

    inboundObserver.onNext(value);

  }



  @Override

  public void onError(Throwable t) {

    inboundObserver.onError(t);

  }



  @Override

  public void onCompleted() {

    inboundObserver.onCompleted();

  }



  @Override

  public void beforeStart(ClientCallStreamObserver<RespT> stream) {

    stream.setOnReadyHandler(onReadyHandler);

  }

}